The present invention relates to a molding method and system with a molding apparatus. More particularly, it relates to a molding method and system with a molding apparatus by which the density of a mold is made uniform, by which little molding sand overflows the molding apparatus, and by which the amount of any molding sand that must be removed from the mold is less compared to the prior art.
A pattern plate is surrounded by a molding frame of a molding apparatus. Generally, the molding frame of the molding apparatus is filled with molding sand by letting it fall from a hopper by gravity. Then the molding sand projecting over the molding frame is swept out by a suitable member so that the upper surface of the molding sand may be flat.
A conventional molding apparatus supplies molding sand on an entire surface of a pattern plate regardless of different heights of the areas of the surface of the pattern plate. Thus, molding sand can overflow a molding frame when the molding sand fills it. Also, the density of the molding sand varies at various areas on a pattern plate according to the different heights of the patterns on the pattern plate, when the molding sand is squeezed.
Also, a conventional molding apparatus usually supplies molding sand to a molding frame at a constant in volume over time, so that the density of the molding sand differs at various positions on the pattern plate, although the feed of the molding sand to the molding frame must properly be changed according to the different shapes of patterns. Thus, when under that state the molding sand is squeezed, the resulting mold can project from the molding frame. In that case, the portion of the mold that projects over the upper level of the molding frame must be removed so that the upper surface of the mold may be aligned with the upper edge of the molding frame. Thus, a large amount of molding sand is wasted. Also, an apparatus for removing the molding sand is required. Also, the molding sand is spread when it is removed.
Accordingly, it is the principle object of this invention to provide a molding method and apparatus for a molding apparatus with a molding frame by which molding sand that overflows the molding frame and that must be removed from the molding frame decreases compared to the prior art, and by which the density of the molding sand within the molding frame can be made uniform after it is squeezed.
Thus, the object is achieved by a molding method for a molding apparatus with molding frames. This method include steps of defining a molding sand filling cavity by means of a pattern plate, a molding frame that can be put on the pattern plate, a filling frame that can be put on the molding frame, and a covering apparatus having a plurality of squeezing feet that can enter the filling frame and that can be temporarily held at certain positions where certain distances are kept between the lower ends of the squeezing feet and surfaces of patterns on the pattern plate, which surfaces are opposed to the lower ends, supplying molding sand to the molding sand filling cavity, and compressing the molding sand by means of the squeezing feet.
The capacity of the molding sand filling cavity is controlled by moving the respective squeezing feet up and down.
Also, the object is achieved by a molding method for a molding apparatus with molding frames wherein the capacity of the molding sand filling cavity is controlled by changing the distances between the surfaces of the patterns on the pattern plate and all the squeezing feet.
The positions of the respective squeezing feet are controlled when any part of the molding sand that is too much or too little is sensed. The distances between the surfaces of the patterns on the pattern plate and all the squeezing feet are controlled when too much or too little molding sand is sensed.
The step of sensing the molding sand that is partially too much or too little or too much or too little molding sand includes the steps of measuring reaction forces of the molding sand to the squeezing feet when the molding sand is squeezed in the molding sand filling cavity, and executing a calculation based on the measurements of the reaction forces.
The molding sand is supplied by supplying compressed air.
The molding sand is supplied through a plurality of nozzles.
The feed of the molding sand is changed by changing the amount of aeration to the nozzles according to the shapes of the patterns on the pattern plate.
A pressurized air flow or a pressurized air surge acts after the molding sand is supplied.
Based on past molding data any one of the capacity of the molding sand filling cavity, the positions and strength of the aeration, and the strength of the pressurized air flow or the pressurized air surge is controlled.
The past molding data is stored in a storage device of a controller of the molding apparatus with molding frames. Before the relevant operations are performed during the molding operation by the molding apparatus with molding frames, optimized values on the capacity of the molding sand filling cavity, the positions and strength of the aeration, and the strength of the pressurized air flow or the pressurized air surge are set.
The past molding data is connected to a computer that stores molding data for another molding apparatus through the controller of the molding apparatus with molding frames. The results of the calculation by the computer are used, so that optimized values on the capacity of the molding sand filling cavity, the positions and strength of the aeration, and the strength of the pressurized air flow or the pressurized air surge are set.
Also, the object is achieved by a molding system with molding frames having a pattern plate, a molding frame than can be put on the pattern plate, a filling frame that can be put on the molding frame, a covering apparatus having a plurality of squeezing feet that can enter the filling frame and that can be temporarily held at certain positions where certain distances are kept between the lower ends of the squeezing feet and surfaces of patterns on the pattern plate, which surfaces are opposed to the lower ends, and a sand supplying apparatus for supplying molding sand to the molding sand filling cavity that is defined by the pattern plate, the molding frame, the filling frame, and the covering apparatus, characterized by sensors for measuring reaction forces to respective squeezing feet, a storage device that stores molding data based on the measurements of the sensors for measuring reaction forces, and a distance calculation device for calculating distances between the lower ends of the squeezing feet relating to the molding sand filling cavity and the patterns on the pattern plate that are opposed to the lower ends of the squeezing feet.
The covering apparatus has a plurality of squeezing feet. They can pass through the plate of the covering apparatus and move up and down so that they jointly form an upper surface of the molding sand filling cavity.
Any molding sand that is partially too much or too little is sensed when the density of a part of the mold is high or low. Too much of too little molding sand is sensed when the density of all the molding sand is measured to be too high or too low.
The reaction forces to the plurality of the squeezing feet act when the molding sand is compressed. Those forces are sensed by respective sensors, for example.
The past molding data includes not only the molding data for the immediately prior molding, but also some molding data previous to it. When the capacity of the molding sand filling cavity etc. is controlled, the immediately prior molding data, as well as the data that is taken based on some of the previous data, is used. Also, the previous molding data is stored as a database, so that based on that data the capacity of the molding sand filling cavity etc. can be controlled by conventional methods such as a method of least squares and a fuzzy control method.
The past molding data is connected through a communication line such as the Internet and radio communications to a computer that stores molding data for another molding apparatus through the controller of the molding apparatus with molding frames.